Water-ring pump



F. NEUMANN WATER RING PUMP May 7, 1929.

Filed Nov. 9, 1925 2 Sheets-Sheet 1 7%MMM Mvenio! y 7,1929- F. NEUMANN 1,711,902

WATER RING PUMP I Filed Nov. 9, 1925 2 Sheets-Sheet 2 lnrah to)" Patented May 7, 1929.

UNITED STATES 1,111,902 PATENT OFFICE.

FRITZ NEUM ANN, OF NUBEMBERG, GERMAJSTY.

- WATER-RING PUMP.

Application filed November 9, 1925, Serial No. 67,979, and in Germany November 11, 1924.

,Water ring pumps, as is known, operate with a ring of circulating liquid which becomes heated owing to its rubbing against the pump casing. This heating must be avoided, because the efficiency of the water ring pump depends on the temperature of the liquid ring, that is to say the efiicienc'y decreases as the temperature rises. For this reason, it has been proposedto allow water ring pumps to suck up some water continuously and discharge it through the outlet pipe of the pump when the latter is arranged as an air pump for a centrifugal pump and is mounted on a common shaft so as to run with the centrifugal pump during the normal operation thereof.

The continuous flowing off of water from the outlet pipe of the water ring pump is very undesirable and is sometimes even di-.

rectly inconvenient, for instance, if the unit consisting of water ring pum and centrifugal pump is employed as a tire extinguishing pump in travelling or portable fireengines. The-water discharged by the water ring pump floods the ground on which the fire engine stands, thus renderin it difficult to mind the engine and even angerous to do so in winter owing to freezing.

This drawback is removed, according to the present invention by shutting off the outlet pipe of thewater ring pump during I the normal working of the centrifugal pump and returning the water sucked up by the former through a by-pass into the suction chamber of the centrifugal pump.

The invention is illustrated by way of example in the accompanying drawing:

Figs. 1 and 2 show cross sections through a water ring pump.

Figs. 3 and 4 show water ring pump con--- nected to a centrifugal pump.

Fig. 5 showsa schematic view of a further modification.

Referring to the drawing, the water ring pump comprises, in known manner, the cylindrical casing 1, the inlet port 5, outlet port 6 and the vane wheel 2 capable of rotating about an axis 3 eccentric to the axis of the casing 1 as well as the circulating water ring 4. The suction port 5 communicates with the suction pipe 5 and the exhaust port 6 communicates with the exhaust pipe 6. When the suction chamber of the water ring pump is filled with water, so that air can no longer pass in, only water will be sucked up through the inlet port 5 and only water will be discharged through the exhaust port 6. The water ring pump then by means of the arrangement according to the present invention.

Referringto Figure 3, the water ring pump 7 is coupled to a centrifugal ump 8, so as to act as an air pump for it. 'l he vane wheel of the water ring pump and the impeller of the centrifugal pump are mounted on the same shaft, so that the former revolves continuously with the latter. The suction chamber of the water ring pump is connected up to the suction chamber of the centrifugal pump through the ports 71 and 72, whilst a pipe 10 branches off from the outlet pipe 9 of the water ring pum said pipe communicating with the suction ranch 11 of the centrifugal pump. At the place where the pipe 10 branches off from the pipe 9, a three-way cook 12 is interposed.

When the centrifugal pump is started up, the water ring pump to commence with sucks in air from the suction chamber of the centrifugal pum and discharges the air through outlet pipe 9. When the priming of the centrifugal pump is completed, the water ring pump will no longer suck up air, but only water. The three-way cook 12 is then actuated so as to place the outlet pipe 9 into communication through the pipe 10 with the suction branch .11 of the centrifugal pump. The water dischar ed from the 'water ring pump can there ore no lon er flow off, but will be returned to the suction chamber of the centrifugal pump, whilst some water will be continuously sucked into the suction chamber of the water ring pump no longer operates as an air pump, but as a I V the water ring pump, but on the contrary may also be drawn off from another point of the water ring ump, for instance through the pipe 15 in igure 2, in which case,- the construction shown in Figure 4 may be adopted. In this case also, the rotor of the water ring pump 7 and the impeller of the centrifugal pump 8 are mounted on the same shaft. The outlet pipe 13 of the water ring pump, however, its not connected up to the suction chamber of the centrifugal pump, but simply communicates with the open air, being only provided with a valve 14: The air pump is connected up by means of a by-pass 15 fitted with a valve 16 to the centrifugal pump, said by-pass establishing communication between a point of the water ring pump at which the pressure is comparatively high and a point of the centrifugal pump at which the pressure is lower.

When water ring pump has removed the air from the centrifugal pump and the former commences to pump water, the outlet pipe 13 will be closed by actuating the valve 14, while the previously closed valve 16 will be opened. Water will now be delivered from thewater ring pump to the centrifugal pump through the by-pass 15 owipg to the pressure of the water in the water ring pump being above that of the atmosphere. In consequence of this withdrawal of water from the water ring pump, water is again sucked up automatically from the suction chamber of the centrifugal pump. In this way a continuous circulation of a small uantityof water will again be produced t rough the water ring pump and centrifugal pump, thereby cooling the water ring.

The cooling of the-water ring need not be effected by passing the water through the centrifugal pump. On the contrary, "it is also possible to circulate the water continuously by removing it from a point at which the pressure is comparatively high and returning it to a point at which the pressure is lower, the water drawn ofl'f being simultaneousl cooled. This mode of cooling is specia y suitable in the case of water ring pumps that are not coupled up to a centrifugal pump.

The construction shown in .Figure 5 comprises a centrifugal pump 1, a' water ring pump 2'acting as air pump and direct coupled to the centrifugal pump, and a cooler 3. The cooling coil 4' of the cooler 3 is connected up at one end to the outlet of the water ring pump 2 by a ipe 5 and at the other end by a pipe 6 to t e suction branch 7 of the centrifugal pump 1, in such a manner that a higher pressure exists in the inlet pipe of the coil 4 than in the discharge pipe.

The cooler 3 itself is in turn a member of a closed circuit comprising the cooling jacket of the pump casing, the pipe 5", the cooling tank 3, the pipe 5, the cooling jacket of the driving motor and the return pipe 5.

When the centrifugal pump 1 is put into operation, the water ring pump 2 first of all draws air through the ports 71, 72 from the suction space of the centrifugal pump 1 and forces the air through the suitably adjusted cock 2 and the pipe 73 to the outside. When the priming of the centrifugal pump 1 is completed then the water ring pump ceases to draw air from the centrifugal pump and only draws water. The cock 2 is then turned round in order to close the path through the outlet pipe 73 into the open and connect up the water ring pump cooling pipe 5 connected to the coil 4. The water forced out by the water ring pump is thus unable to flow into the open but can only flow through the pipe 5, coil 4 and pipe 6 into the suction branch 7 of the centrifugal pump 1, the water thus flowing tinuous circuit from the water ring. pump 2 through the cooling coil 4 of the cooler 3'to the centrifugal pump 1. The cooling coil itself is surrounded by the cooler 3 which forms part of a second circuit, the water in which flows from the'cooling jacket of the centrifugal pump 1 through a pipe 5*, the cooling tank 3, the pipe 5", the. coolln jacket of the driving motor and the pipe 55iack to the cooling jacket of the centrlfugal pump 1.

1. The combination with a centrifugal pump and a water ring pump for withdrawmg air from the centrifugal pump, said water ring pum having an outlet for the discharge of flui drawn into the water ring pump from the centrifugal pump, of means for establishing open communication between said outlet and the suction chamber of the centrifugal pump for enabling water to return to the said suction chamber from the water ring pump when the centrifugal pump .is drawing water, and a shut-off device for interrupting the communication between the water ring pump and the centrifugal pump 2 to the.

ina conthrough said means, for the purposes set I forth.

2. The combination with a centrifugal pump and a water ring pump for withdrawing air from the centrifugal .pump, said water ring pump having an outlet for the discharge of fluid drawn into the water communication between said outlet an sue tion branch pi e, for the urposes set forth.

3. The com ination with a centrifugal pump and a water ring pump having a suction chamber in open communication with the suction chamber of the centrifugal pump and an outlet for the discharge of fluid drawn into the water ring pump from the suction chamber of said centrifugal pump, of an outlet pipe in 0 en communication with the outside air an connected to said outlet for receiving fluid discharged by the water ring pump, a connecting pipe for establishing .open communication between the suction chamber of the centrifugal pump and the outlet side of the water ring pump, a valve for shutting off the outlet pipe from the outside air and a valve for closing said connecting pipe for the purposes set forth.

4. The combination with a centrifugal pump and a water ring pump having a suction chamber in 0 en communication with the suction cham r of the centrifugal pump, and an outlet for the discharge of fluid drawn into the water ringpump from the suction chamber of said centrifugal pump, of an outlet pipe in open communication with the outside air and connected to said outlet for receiving fluid discharged by the water ring pump, a connecting pipe for establishing open communication between the suction chamber of the centrifugal pump and the outlet side of the water ring pump, and a three-way cock for shutting off the outlet pipe from the outside air and for closing said connecting pipe, as and for the purposes set forth.

5.1-The combination with a centrifugal pump and a water rin' pump for withdraw mg air from the centrifugal ump, and having an outlet for the disc arge of fluid drawn into it from the centrifugal pump, of

circulating means for establishing open communication between said outlet and the suction chamber of-the centrifugal pump for enabling water. to circulate between the I water ring pump'a'ndthe centrifugalpump when the latter is drawing water, a; cooling coil interposed in said circulatingmeans and a shut-off device for'int'erruptin the communication between the-outlet og'thewater ring pumpand thecentrifugal pump through said circulating me'ans, for the'pur poses set forth.

In testimony whereof aflixmysignature;

. FRITZ 

